05 rear veiw mirror resets repeatedly - and headlights stay on

on my 05 this stupid *** rear veiw mirror keeps blinking off and resetting randomly, untill i drive for about 20 minutes then it will quit. its the airbag on/off lights, compass / temp display and auto dim. the onstar buttons remain lit up.
the biggest bitch of this is when i shut off the auto dim mirrors for when im towing my trailer so i can see it at night, the f-ing thing resets and turns it right back on then the side mirror goes dark.... how can i just disable the auto dim? im about to clip all the wires to the rear veiw.
the headlights are on constantly now also, brightest high noon sun shining right on the dash and they will come on.
im really beginning to dislike this truck, i shoulda bought a toyota.
one thing i know for a fact is that my battery is getting weak... do you think that could have an effect on the mirror from voltage dips and spikes?
its got a half dead cell and sits at 11.0v, havent made it to get a new batt yet, but it is on my to do list this week.
it will not start the truck after 8 mins of the headlights being on. when the ABS activates(which is #1 on my list of things to disable) i get 10.0 volt drops from ~14.2, that cant be helping matters much.